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51.
Using DAPI, rabbit antitubulin antibody, FITC-labeled goat anti-rabbit IgG, and TRITC-phalloidin to stain individual cells, the microspectrophotometric analysis showed that three markers that represent the nucleus, microtubules (MT), and microfilaments (MF), respectively, could be recognized in individual cells without interference. The phase of the cell cycle was determined by DNA content. We found that in Indian muntjac (IM) cells, the amount of tubulin in G2 and M phases was about twice as much as that in G1 phase. In G2 cells, the cytoplasmic microtubule complex (CMTC) became denser than in G1 cells. The cytoplasmic MT extent in basically the same orientation as MF bundles in interphase. The regions where the MT is denser also have a denser MF distribution. 相似文献
52.
The alpha-like globin gene cluster in rabbits contains embryonic zeta-
globin genes, an adult alpha-globin gene, and theta-globin genes of
undetermined function. The basic arrangement of genes, deduced from
analysis of cloned DNA fragments, is 5'-zeta 0-zeta 1-alpha 1-theta 1- zeta
2-zeta 3-theta 2-3'. However, the pattern of restriction fragments
containing zeta- and theta-globin genes varies among individual rabbits.
Analysis of BamHI fragments of genomic DNA from 24 New Zealand white
rabbits revealed eight different patterns of fragments containing
zeta-globin genes. The large BamHI fragments containing genes zeta 0 and
zeta 1 are polymorphic in length, whereas a 1.9-kb fragment containing the
zeta 2 gene and the 3.5-kb fragment containing the zeta 3 gene do not vary
in size. In contrast to this constancy in the size of the restriction
fragments, the copy number of the zeta 2 and zeta 3 genes does vary among
different rabbits. No length polymorphism was detected in the BamHI
fragments containing the theta-globin genes, but again the copy number
varies for restriction fragments containing the theta 2 gene. The alpha 1-
and theta 1-globin genes are located in a nonpolymorphic 7.2-kb BamHI
fragment. The combined data from hybridization with both zeta and theta
probes shows that the BamHI cleavage pattern does not vary within the
region 5'-alpha 1-theta 1- zeta 2-zeta 3-theta 2-3', but the pattern
genomic blot-hybridization patterns for the progeny of parental rabbits
with different zeta-globin gene patterns shows that the polymorphic
patterns are inherited in a Mendelian fashion. Two different haplotypes
have been mapped based on the genomic blot-hybridization data. The
variation in the alpha-like globin gene cluster in the rabbit population
results both from differences in the copy number of the duplication block
containing the zeta-zeta-theta gene set and from the presence or absence of
polymorphic BamHI sites.
相似文献
53.
周吉源;程井辰;王家训 《武汉植物学研究》1988,6(1):45-48
油菜花序轴、叶片在MS培养基上经诱导可产生愈伤组织并形成再生植株。愈伤组织形成可分3个时期:细胞启动期、分裂期和分化期。实验证明:花序轴启动部位多发生在皮层薄壁细胞、髓部薄壁细胞、韧皮薄壁细胞和木薄壁细胞。叶片主要是叶肉细胞、叶脉薄壁细胞和表皮细胞启动。细胞分裂期的特点是启动细胞反复增殖,形成连续的分生细胞层。细胞分化期的特点是一部分细胞保持分裂能力,一部分细胞分化形成薄壁细胞和输导分子。观察了愈伤组织中器官发生的部位和方式。实验证明,根的发生多为内起源,芽的发生多为外起源。 相似文献
54.
<正> 5S rRNA是一种稳定的独立小分子,在原核和真核细胞中都牢固地结合在核糖体的大亚基上。它在蛋白质生物合成过程中具有重要作用。微生物、大鼠肝细胞及某些植物细胞5S rRNA的一级结构都已经测定,脑细胞5SrRNA的一级结构尚未见报道。因此,我们对幼龄小鼠全脑5S rRNA的序列进行了分析。我们用辜祥荣等人的方法分离和纯化5S rRNA,5S rRNA3′-末端标记参照Peattie的方法(2)。3′-末端标记5S rRNA的序列分析用化学降解-凝胶直读法及特异RNa8e降解直 相似文献
55.
56.
57.
Summary Three cases of Y chromosomal aberrations were studied using a panel of Y-specific DNA sequences from both Yp and euchromatic Yq. One case was a phenotypic male fetus with a Y-derived marker chromosome. The short arm of this chromosome was intact, but most of its long arm was missing. The second case had a 46,Xyq- karyotype with portions of euchromatic Yq, including the spermatogenesis region, missing. The third case was a phenotypic female with a 46,XXp+ karyotype. The extra material on the Xp+ chromosome was derived from the heterochromatic, and part of the euchromatic, portion of Yq. Application of X-specific DNA sequences demonstrated that the distal portion of the short arm of the translocation X chromosome was deleted (Xpter—p22.3). The three examples demonstrate the importance of diagnostic DNA analysis in cases of marker chromosomes, and X and Y chromosomal aberrations. In addition, the findings in the patients facilitate further deletion mapping of euchromatic Yq. 相似文献
58.
Type V collagen is a fibrillar collagen that is widely distributed in tissues as a minor component of extracellular matrix and is usually composed of one pro alpha 2 (V) and two pro alpha 1 (V) chains. In this report, recently isolated cDNA and genomic clones, which encode the pro alpha 1 (V) chain, are used as probes for hybridization to filter-bound DNA from a panel of human-mouse hybrid cell lines and for in situ hybridization to metaphase chromosomes. These studies establish the chromosomal location of the COL5A1 gene, which encodes the pro alpha 1 (V) chain, within segment 9q34.2----q34.3. These findings add to the previously characterized dispersion of collagen genes in the human genome, as this is the first example of a collagen locus on chromosome 9. In addition, these studies place COL5A1 near the locus for the genetic disorder, nail-patella syndrome (hereditary osteo-onychodysplasia), which also maps to 9q34. 相似文献
59.
Nitric oxide synthesis in the CNS endothelium and macrophages differs in its sensitivity to inhibition by arginine analogues. 总被引:9,自引:0,他引:9
L E Lambert J P Whitten B M Baron H C Cheng N S Doherty I A McDonald 《Life sciences》1991,48(1):69-75
Inhibition of nitric oxide production by arginine analogues was examined in three cell systems; macrophages, CNS tissue and endothelial cells. Nitric oxide production was assessed indirectly using in vitro assays measuring nitrite production (macrophages), cGMP elevation (CNS) and acetylcholine-induced relaxation of aortic ring segments (endothelium). NG-monomethyl-L-arginine and NG-amino-L-arginine possessed similar inhibitory activity in all three assays, while NG-nitro-L-arginine displayed a striking selectivity for inhibition of brain and endothelial cell nitric oxide synthesis, with IC50 values of 0.05 microM in the CNS versus 200 microM in macrophages. These results suggest that distinct enzymes are responsible for nitric oxide synthesis in different cell types, and indicate that it may be possible to selectively modulate nitric oxide production in vivo. 相似文献
60.
The differential regulation of the two nitrate reductase (NR, EC 1.6.6.1) genes of Arabidopsis thaliana L. Heynh was examined. cDNAs corresponding to each of the NR genes (NR1 and NR2) were used to measure changes in the steady-state levels of NR mRNA in response to nitrate, light, circadian rhythm, and tissue specificity. Although nitrate-induction kinetics of the two genes are very similar, NR1 is expressed in the absence of nitrate at a higher basal level than NR2. Nitrate induction is transient both in the roots and leaves, however the kinetics are different: the induction and decline in the roots precede that in the leaves. Light induces the expression of each of the genes with significantly different kinetics: NR2 reached saturation more rapidly than did NR1. Both genes showed similar diurnal patterns of circadian rhythm, with NR2 mRNA accumulating earlier in the morning. 相似文献